Method of converting the energy of alternating electric currents into effective mechanical energy.



M M www No. 664,733. Patented Dec. 25, |900. R. EICKEMEYER, Decd.

R. EICKEMEYER. lr. & C. & M. T. EICKEMEYER, Executors.

METHOD 0F CCNVERTING THE ENERGY 0E ALTERNATING ELECTRIC CURRENTS INTOEFFECTIVE MECHANICAL ENERGY.

(Applimion filed Nov. 21, 1892.)

(No Model.) 3 Sheets-Sheet I.

Ien

IIMII Patented Dec. 25, |900. R. EICKEMEYER, Decd.

n. Elckaulzvan, 1r. & c. a ul. T.A :1cm-:Mavim executors. METHODOFCONVERTING THE ENERGY 0F ALTERNATING ELECTRIC CURRENTS INTO EFFECTIVEMECHANICAL ENERGY.

(Application led Nov. 2 1'892.) (N0 lodel.) 171 y3 Sheets-Sheet 2.

I lll 1 Tn; Non rcm co. maro/uma., wmmom. nA c.

No. 664,733. Patented Dec. 25, |900. R. EICKEMEYER, Decd. n. ElcKEuEvEmJr. a c. a M. T. EICKEHEYEH, Executors. vIIIETHUD 0F CONVERTINGI THEENERGY 0F ALTERNATING ELECTRIC CURRENTS INTO EFIECTIVE MECHANICALENERGY.

(Applicnton Bled Nov. 21, 1892.) (No Nudel.) v 3 Sheets-Shut 3.

UNITED STATES RUDOLF EICKEMEYER, OF YONKERS,

PATENT OFFICE.

NEWv YORK; RUDOLF EICKEMEYER,

JR., CARL EICKEMEYER, AND MARY T. EICKEMEYER EXECUTORS OF SAID RUDOLFEICKEMEYER, DECEASED.

METHOD OF CONVERTING THE ENERGY 0F ALTERNATING ELECTRIC CURRENTS INTOEFFECTIVE MECHANICAL ENERGY.

SPECIFICATION forming part of Letters Patent No. 664,733, dated December25, 1900;

Application filed November 21,1892. Serial No. 452,607. (No model.)

To all whom, t may concern,.-

Be itknown that I, RUDOLF EICKEMEYER, of Yonkers, in the county ofWestchesterand State of New York, have invented a certain new and usefulMethod of Converting the Energy or Electromotive Force Aof AlternatingElectric Currents into Effective Mechanical Energy; and I do herebydeclare that the following specification, taken in connection with thedrawings furnished and forming a part of the same, is a clear, true, andcomplete description of my invention.

In my application for Letters Patent tiled December l, 1890, Serial No.376,361, I disclosed certain improvements in alternatingcurrent machinesas variously devised by me, and said application contained duereservation in and to the disclosed method invented by me for securingeffective mechanical energy from alternating electric cnrrents,saidmethod consisting, mainly, in the elimination of counter electromotiveforce of self-induction by establishing biiilar or inductionlesscircuits wherever armature self-induction would have been developed hadnot said inductionless circuits been established,land, further, mymethod consists in reducing selfinduction by the introduction ofair-space resistance into appropriate portions of armature magneticcircuits, and, still further, reducing self-induction by working astrong armature-ft'. e. ,one having` numerous ampereturns-in acomparatively weak magnetic field, and various other improvements to behereinafter described and claimed.

It is well known that ordinary series motors containing laminatedfield-iron may be put int-o motion by the use of an alternating electriccurrent; but such machines cannot practically or effectively affordmechanical energy because of the development of counter electromotiveforce of self-induction to such a high degree as to demand excessivevoltage for forcing the current through the windings of the armature andiield, thereby endangering the machines, and aside from that they are ofno practical value because only a very low proportion of theelectronictive force of the supplied current can with such machines beconverted into mechanical energy, and this is so true of all prioralterhating-current machines of which I am cognizant as to render themof little practical or commercial value. I have discovered anddemonstrated that field self-induction is materially decreased byworkingl a weak lield withacomparativelystrongarmature. Vhen working astrong armature in a weak field, the counter electromoti ve force whichshould be eliminated is due to self-induction ot' the armature, and Ihave also discovered and demonstrated that armature self-induction canbe practically eliminated by forming biiilar or ind uctionless circuitsat appropriate portions of the armature-circuits, and thereby defeatingthe development of such armature magnetic circuits as would otherwisegenerate or cause self-induction. I have also discovered anddemonstrated that the introduction of air-space magnetic resistance intoappropriate portions of armature magnetic circuits will materiallyreduce armature selfind uction,and especially when employedsupplementary to the aforesaid forming of bitilar circuits.

In the conversion of the energy of alternating electric currents intomechanical energy by the use of machines as heretofore organized, thearmature-circuits are exposed to great dangers, as from burning, dac.,resulting from the short-circuiting of coils, wherein an electromotiveforce is induced d uring theircom mutation. I have discovered that saiddangers are wholly obviated by introducing into the commntated circuitsan electromotive force of appropriate strength and opposite direction toand balancing the eleclromotive force acting therein, or as a partial orimperfect equivalent thereof introd ncing resistance, so as to reducethe current produced by the electromotive force of the commutated coilsto a safe limit, or by employing both said resistance and the saidopposing electromolive force, and these meth- Figure l, in longitudinalvertical section,-

illustrates an alternating-current machine which in operation involvesmy said novel method. Fig. 2 illustrates said machine in end View, butwith the commutator-bars in section. Fig. isa central verticalcross-section of the same. Fig. 4.- is a diagrammatic illustration ofthe electric and magnetic system of the machine. Fig. 5 illustrates aportion of the coinmutator in plane projection, some of thearmature-coils, one set of the commutator-brushes, one line-wire, andcertain special coils which are in direct communication with thebrushes. Fig. 6 illustrates the field metal of the machine and thearmature Without any of the coils shown in Fig. 3, but with variousmagnetic circuits indicated in dotted lines.

Although the Working of my said novel method is in no manner restrictedto machines having any special polar arrangement, it will be describedin connection with a bipolar machine, although a multipolar machine wasalso disclosed in my aforesaid application for Letters Patent.

ln the bipolaimachine, Figs. l, 2, and 3, the inclosing structure orframe includes the field-magnets, consisting of a base portion A and atop portion A. 'lhese two sections are united on a horizontal line in aplane with the axis of the armature-shaft by means of' short verticalbolts. The base-section consists in part of two end plates a, n', eachaffording a support for the journal-bearings. The top section consistsin part of two end plates a2 c3. The iron or field-magnet metal affordsseparate magnetic field-circuits and is in four separate masses orbodies b b and cc', and these are mounted between four skeletonizednon-magnetic plates or brass castings d d d2 cl3, and all are clampedtogether by means of well-insulated bolts. The masses b and b' arelaminated, being composed of insulated light thin plates of soft iron,each of horseshoe form and each mass affording concave cheeks or facesat h2, and between said faces there is a central longitudinalrectangular recess, and one of said masses is above and the other belowthe circular space occupied by the armature B. The masses of iron c care also laminated, and they are somewhat similar to the masses b b inform, and each is large enough to inclose the adjacent mass b or b. andto afford large intervening spaces, as at c. The iron plates of themasses c c at their inner ends afford concave cheeks or pole-faces c2;but said ends are separated on a horizontal line by a space about equalto the distance between their concave faces and the armature; butoutwardly said ends angularly diverge and form V- shaped spaces, asshown in Figs. 2, 3, and (i. The spaces c being parallel with the pathsof the field magnetism do not operate as airspace resistances in thefield-magnet circuits; but said spaces c, as well as the V-shaped spacesbetween the upper and lower masses of iron c and c, constitute air-gapswhich intersect the armature magnetic circuits and afford desiredresistance therein, as will be hereinafter further explained.

The armature Bis surrounded longitudinally in a vertical plane by a mainlield-coil f, which has straight sides housed in the central recesses ofthe masses of iron h and said coil is made in two properly-coupledsections or halves which at their ends are so bent or curved as toafford the space occupied by thearmature-shaft. This mainiield-coilconta-ins a small number of convolutions, and its excitingcapacity is weak as compared with that of the armature-winding. Closelysurrounding the field-coil and conforming thereto are other coils, eachseparate from the main field-coil, although of course they may all bemechanically united and handled as if they were two halves of a largefieldcoil. These other coils cannot well be separately shown in Fig. 3;but it is to be understood that conforming in shape with the ieldcoilthere are live independent but closely contiguous coils which will bespecially described and designated as isolated coilsf, f2,f3, f4, andf5, as shown in Fig. -l-. The duty oi' four of these coils is to guardthe armature-coils while they are passing under brushes and to eliminateas far as possible that portion of the electromotive force which byrapidly-varied field magnetism is induced in those armature-coils whichfor the time being are passing under the main commutator-brushes, aswill be hereinafter explained. Each of the coils j", j2,f3, and flcontains a few turns of coarse wire, and the coilf, hereinafterdescribed, contains a greater number of turns of fine wire. The armatureB is also closely surrounded longitudinally in a horizontal plane byanother field-coil which I term the coi1ntertield,and this is alsoconstructed in halves, and its ends are inside of the ends of the. mainfield-coil and lie parallel with the ends of the armature, above andbelow its shaft, and its straight sides Iill or occupy the tl-shapedgaps or spaces between the upper and lower masses of iron c c", and theyare closely adjacent to and overlie the armature-Winding. Two otherhorizontallyarranged counter field-coils g g2 surround the innerportions of the iron field masses b and b', the sides of said coilsfilling the gaps or spaces between the inner and outer portions of thefield iron masses b and c and b and c. The ends of said coils areparallel with the adjacent portions of the ends of the armature,

IOO

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but outside of the ends of the main Iield-coil f, and their sidesclosely overlie the armaturewinding. These counter field-coils g g g2are coupled. together in series and coupled in series with the mainiield-coil and also with the armature-coils. Each portion oi' thecounter iield forms with such adjacent and parallel port-ions of thearmature-coils as are overlaid by it (and in which the current is inopposite direction) a biiilar electric circuit, which is theoreticallyfree from self-induction, at least the counter eld practicallyneutralizes selfinduction in the armature-circuit, and its action issupplemented by the action oi' the airgap resistances, and, stillfurther, by working a strong armature in a weak field, which materiallyreduces the self-induction ofthe field. The armature embodies windingsh, substantially corresponding with the winding of continuous-currentarmatures of the Paccinotti type, and, like those,the core of saidarmature B is toothed or longitudinally scored on its periphery; butitis ofdrum form, andthe core is composed ot" thin notched disks t of softiron well insulated.

As thus far described, it will be seen that the laminated iron in thefield is in several comparatively small masses, and hence the undueformation of magnetic uxes about the armature electric circuits isgreatly obviated, which proportionately decreases the counterelectromotive force of self-induction.

The iron in the armature-core is laminated, as

in ordinary machines, and hence is capable of responding rapidly tomagnetic variations.

The coinmutator C is shown in section in Figs. l and 2 and partially inplane projection in Fig. 5. In this coinmutator there is a set of longcomparatively wide bars Zt, to each of which the terminals ofappropriate armature-coils h are connected. Between these live bars Ztthere are narrow dead bars divided into three equal lengths, as at Z ZZ2, and these are insulated from each other and from said wide livebars, and they have no electric connections. Vith this commutator(illustrated in Figs. 2, 4, and 5) four sets of brushes are employed,one set being triple and the other double. The triple setsm, m', and 'm2and m3, 'm4, and m5 are opposite each other on a horizontal line, andthey maintain a circuit from the line-wires through the armature-coils.The two sets of double brushes n 'n' and n2 n3 are located in a line atright angles or perpendicular to the real commutator-brushes, and theyare in this machine connected with a coil or coils f5, which are notconnected with the live circuit, as is clearly indicated in Fig- 4. Thebrushes of the m series are alike, each brush being provided withseveral carbon contacts in line with each other in each brush; but thecontacts in the three brushes of each set occupy dii-'ferent lines, sothat when the two outer brushes bear upon two separate long bars Zt themiddle one will bear upon one of the narrow Short bars Z, as shown inFig. 5, and also so that when the two outside brushes bear upon shortbars Z and Z the middle brush will bear upon an intervening liveloar Zt.The double brushes of the n series separately considered are like eithertwo of the other brushes, and each brush alternately bears upon a livebar Z: and a dead bar Z or Z, as the case may be.

Referring now to Fig. 4, it will be understood that the armature B, itswindings Zt, and the coni uiutator-bars Z5 and Z are shown in diagramonly. The fleld-coilfis also shown in appropriate relation with theisolated coils ffffi, and f5, while the counter fields are shown at g,g', and g2 massed in one coil. rPhe line-wires are shown at E and E',and, commencing with the wire E, the electric connections will befollowed by the use 'of numerals for designating the several wires orconductors. rThe line-wire E connects with a terminal l of the counterfields g g g2, thence by wire 2 with one terminal of the true or mainfield-coil f, thence from its other.

terminal by wires 3 and 4 connects with the middle brush m of one set,and through it with a live bar Zt and one terminal ot' each twoarmature-coils Zt Zt. The wire 4 at wire 5 shunts to a resistance atrand thence by wire 6, which branches to adjacent but opposite terminalsofthe extra or isolated coils f f2, and the other terminals of thesecoils are separately connected by wires 7 and 8,1espectively, with thebrushes m and m2, which, as here shown, are resting on dead bars Z, andhence said coils are not in this position of the commutator inconnection with the armature circuit. The other terminal line-wire E'isreached at wire 9 from the armature-circuit by way ofthe middle brushm3, which, as here shown, is resting on a live commutator-bar Zo, andhence it connects with one terminal of each of two armature-coils hh. Ashere shown, the brushes m4 and m5 rest on dead bars Z. When said brushesare in contact with live bars, the armature-ci rcnit and line-wire E'are connected, by way of the wire lO, isolated coils f3 f4, and wires 1land l2, to brushes mland m5, respectively,a resistance r between wires 0and 10 being common to both brushes and to both oi' said isolated coils.Vith the brushes m and malso resting on live bars the isolated coils fand f2 will be then in circuit by way of wires 4, 5, 6, 7, and 8, andthe circuit will also then include a resistance r between wires 5 and 6.When the current traverses the isolated coils, it is in oppositedirections, and hence in some of said coils the current flows oppositeto the direction ofthe current in the field-coil, the isolated coilsthus balancing each other and without aiecting the exciting capacityofthe field-current. The fifth coilfis in communication with portions ofthe armature-coils by way of the four brushes of the 'a series, whichrest upon opposite sides of the commutator, so that always at least oneof these brushes is in connection with a live bar on a lineperpendicular to the horizontal commu tator-line on which brushes of them series IOO IIO

IIS

are located. One terminal of the coil f, by way of wire 13, connectswith brush n at the upper side of the commntator. The brush n, by way ofwire 14, also connects with coil f5, but at certain positions of thecommutator short-circuits some of its convolutions, as clearlyindicated. The other terminal of the coil f5, by way of wire 15,connects with a brush n2, while the brush n3, by way of wire 16, in likemanner short-circuits upon a few convolutions at that end of the coilf.In the position here shown it will be seen that the two brushes n n arebearing upon a live bar t, and the diametrically opposite live bar 7c isalso in like contact with the brushes n2 n3. Each of the wires 13, 14,15, and 16 is provided with a resistance 0'. With a slight rotativemovement of the armature the brush n (for instance) will still rest on alive bar 7.5, and brush 'nf will rest on a dead bar, and so also willbrush n3 rest on a live bar and brush n2 on a dead bar, and a stillfurther movement will place all four of the brushes on live bars, and soon. The brushes of the n series are located at those points of theeommutator between which the counter electromotive force ofself-induction which is induced by the pulsations of the alternatingcurrent in the ield is at its maximum, and this portion of the saidelectromotive force is balanced or neutralized by an equal electromotiveforce of opposite direction induced by the varying field magnetism ofthe isolated coil f5, Fig. 4, which, as before stated, is in closeproximity to the main fleld-coilf. Should the field magnetism eX- ceedthe armature magnetism, the electromotive force in the coil f5overpowers the electromotive force between the brushes n, n' and n2 n3and sends through the armature a current which tends to produce ashifting of phase in the armature magnetism. These four brushes of the nseries and their isolated coils constitute a circuit which has no directconnection with the main line, but which affords (or contributes to) aneffective regulation of the counter electromotive force of selfinductionin the armature.

In the conversion of the energy of alternating electric currents intomechanical motion my method of obviating the short-circuiting of thearmaturecoils as they come under the brushes is completely effective inpreventing` the burning out of the armature-winding,and this portion ofmy invention will be now described.

In position as shown in Fig. et the two lineterminals, by way of theopposite fm series brushes and live bars 7e 7c, are in full connectionwith the armature-circuit. The armature and commutator on being slightlyrotated in either direction will enable two brushes of each m set tobear on one live bar 7c, and each of these brushes will then carryitsproportion ot' the current. The isolated coils f f2 fsfl will meantimebe short-circuited through the resistances r r in the conductors 5 6 and9 10.

centres These resistances should be of such capacity as to decrease orrestrict to a moderat-e value the current caused by the counterelectromotive force induced in the coilsfffg, and f4. The suggestedmovement of the armature and commutator will also cause one brush of then series to bear upon the next live bar, and hence all four of thebrushes will then connect with four live bars and with thearmature-coils connected with said bars. The said armature-coils willalso be in circuit with the isolated coils ff2 f3 f4, and theelectromotive force induced therein by the rapidlyvarying eld magnetismwill-counterbalance a part of the electromotive force induced in thesearmature-coils by the field magnetism, while the resistances o" fr willdecrease to a moderate degree the current set np by that part of theelectromotive force which is induced in the armature-coils which is notcounterbalanced by the isolated coils. With the armature still furtherrotated the middle brushes m and m3 will rest on middle dead bars ZQ andthe outer brushes of each set will rest onx separate live bars 7c, andboth will carry current as before; but the armaturecoils connected withsaid bars will be in circuit with the isolated coils or with the latterand resist-ance, as illustrated in Fig. 5, and thus a portion of thecounter electromotive force induced in said armature-coils will bebalanced. It will now be seen that no armature-coil is evershort-circuited 5 but each as it passes the brushes is always in circuitwith at least one resistance 0 and with at least one isolated coil ofthe f' f2f3f4 series.

That portion of inyinvention which consists in balancing theelectromotive forces of the commutated armature-circuits by opposingsaid forces with or by appropriately strong and opposite electromotiveforces is mainly accomplished by the described arrangement of thebrushes of the m series and the isolated coils ff2f3f4 and fullyaccomplished when supplemented by the resistances between said coils andthe brushes. The resistances, however, are very elective in obviatingthe shortcircuiting of the armature-coils by reducing the currentsproduced by the electromotive forces generated therein to safe limits.

Having described the several electric connectionsseparatelyJ willnowbrietly describe the path of the alternating current through themachine, as shown in Fig. L1.

The current entering at E passes through the counter-field g g g2 intothe main eldcoil f and therefrom over wire 3, which has two branches 4and 5. On branch 4: it goes by direct path to the middle brush m to thearmature-circuit. Should the brushes 911, and m2 be resting on livebars, the path would then be by way of branch 5, through resistance r,to wire 6, which divides, so that one path would be by Way of coilf towire 8 and brush m2 and another path in au opposite direction by way ofcoil f2 to wire 7 and brush m to the two live bars la. From the brushesIOO IIO

m m' on? the current passes in two paths upward and downward through thearmaturecoils to the opposite brushes m3, m4, and m5. From thearmature-circuit the current has exit by Way of the brushes m3 m4 m5, inpart directly by way of brush m3 and wire 9, to line-wire E'; but whenthe brushes m'1 and m5, or either of them, rests upon a live bar it theexit from brush m4 is over. wire i1, through isolated coil f3, to wire10, and through resistance 'r to wire 9, `and thence to line-wire E',and from brush m5, over Wire l2, to and through the isolated coilfi towire l0, through resistance r to wire 9, and thence Lo linewire E'.

Referring now to Figs. 3 and 6, it will be seen, as before stated, thatthe field magnetic system is divided into two main portions, one beingwholly above and the other below the axial line of the armature. Each ofthese two portions is divided into two parts, the magnetic circuits ofeach crossing portions of the armature-core, the one traversing a partof the core and the magnetic metal l) or b', as at F and F, Fig. 6, andthe other, as at F' F', traversing the core and the magnetic metal o orc', thus inducing poles N and S on a horizontal line. There being nobreaks or airspace resistance in either of these four divisions of thefield magnetic circuit except those which essentially occur between themagnetic cheeks and the armature, it will be obvious that the machinehas field magnetic circuits of very llow resistance. The particularportion of the armature magnetic circuit which must be speciallycontrolled for eliminating self-induction is also divided into twoparts, one of which is located at the right and the other at the lefthand side of the armature, as shown in Fig. 6 by dotted lines indicatingmagnetic circuits at D and D', the armature-winding as a whole inducingin the armature-core 'n ands polarity above and below its horizontalaxial line.

Minor portions of the armature magnetic circuit which are profitablycontrolled for the elimination of self-induction are located at the fourpoints between the coincident portions of iron b and c and b' and c',there being at those points four magnetic circuits, (indicated in dottedlines and designated D2, D3, D4, and D5,) as shown in Fig. 6. It willnow be observed, as shown in Fig. 3, that the main portion of thecounter-field, as at g, is located within the principal magneticcircuits D and D' of Fig. 6 and that the minor portions of thecounter-iield, as at g' g2, are located within the magnetic circuits D2,D3, D4, and D5. The uxes due to the armature magnetomotive forces whichmight exist in these several magnetic circuits are balanced,neutralized, or eliminated by the counter-field, because the latteraffords magnetomotive forces which are always opposite in direction tothe direction of said magnetomotive forces,

or, otherwise stat-ed, the magnetism whichwould have been induced byadjacent armature-coils in said circuits at D D', &c., is not induced atall, because the current in the counter-field and the opposite currentin the adjacent armature-winding forms bitilar or inductionlesscircuits, which are incapable of developing magnetism. It will also beob,- served that the anti-inductive action of the counter-field isaugmented by the air-space resist-ances afforded mainly at the V-shapedspaces at. the two sides of the armature in the magnetic circuits D D',and, further, at the four spaces occupied b v the portions g' and g2 ofthe counter-field in lhe magnetic circuits D2, D3, D4, and D5, thuscausing each of said circuits to be of relatively high magneticresistance. If such air-space resistance should alone be relied upon forreducing self-induction of the armature, valuable results would accrue;but when accompanied by the bifilar circuits the armature self-inductionis practically eliminated. The counter electromotive force ofself-induction which would have been developed by the iield ismaterially reduced by working a strong armature in a weak field, itbeing obvious that the few convolutions of wire in the main field-coil hhas a weak magnetic exciting capacity, as hereinbefore set forth.

Now, referring to the bililar circuits, on which main reliance is hadfor eliminating counter electromotive force of armature selfinduction,it is obvious that the required biilar circuits are not mere conductors,nor are they necessarily due to the presence of specially-formed coils,so long as paths are afforded closely adjacent to the armature-windingfor a neutralizing-current iiowing in an opposite direction to that ofthe current in the adjacent armature-coils and so proportioned theretoas to form the bifilar or inductionless circuits-as, forinstance, in myaforesaid application I disclosed coils each of which serves at onepoint as a field-coil and at another point as a cou nter-fieldcooperating with adjacent coils of the armature in forming a bifilarcircuit.

It will be seen that the short-circuiting of the armature-coils is animpossibility, thus securing in my machines those good results whichwould be incident to neutral lines.

So far as my knowledge extends I am the first to devise and constructalternating-current motors capable of starting promptly under load andwith which in the event of a non-rotation of the armature Linder fullcurrent no liability exists of burning out the armature-coils, thisbeing rendered impossible because said coils cannot be short-circuited.This capacity for promptly starting under ordinary load is due to thepractical elimination of counter electromotive force of selfinduction,and said elimination is mainly due to the employment of the method whichconstitutes the main feature of my invention and consists in practicallyeliminating armatu re self-induction by establishing biilar or inductionless circuits at appropriate portions IZO of the armature-circuit.The practice of this last-recited method in itself assures a practical,effective, economical, and commercially valuable conversion of theenergy or electromotive force of alternating currents into mechanicalenergy. If the aforesaid method be supplemented or enlarged by theintroduction or employment of air-space resistance in appropriatearmature magnetic circuits, much greater mechanical energy will beassured, the supplied alternating current remaining the same, becausethe said introduction of air-space resistance constitutes in itself aneffective method of reducing self-induction in alternating-currentmachines. So, also, will the resultant mechanical energy be increasedwith the saine supplied current if the before-recited method or methodsbe again supplemented by working strong armaturecircuits withincomparatively Weak field-circuits, because thesaid working constitutesan eective method of reducing self-induction in alternating-currentmachines. These three specified modes considered separately or as acomplex method of working alternating currents pertain to theelimination of self-induction from alternating-current motors. It istherefore to be understood that the best results will accrue from theworking of alternating electric currents in accordance with that complexmethod which includes not only the prime method (which constitutes themain feature of my invention) but also all of the minor or supplementalmethods of reducing self-induction. If, however, the said minor methodsshould be worked alone or together as a complex method or methods,greater mechanical energy can be derived from alternating currents of agiven potential than from alternating-current machines operating underany prior method or methods known to me, although none of the resultsattained from working said minor or supplemental methods would comparefavorably With those assured from the working of my prime method aloneand especially when supplemented by either or all of the recited minormethods.

Although I have described my invention in connection with operatingbipolar machines, itis to be understood that my method or methods can asWell be applied to operating multipolar machines, and whether they bereversible or non-reversible, all of which was disclosed in my aforesaidapplication for Letters Patent.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The method substantially as hereinbeforedescribed, of converting the energy of alternating electric currentsinto effective mechanical energy,Which consistsin eliminating counterelectromotive force of self-induction from alternating-current machines,by establishing bifilar or inductionless circuits at appropriateportions of ar mature-circuits where` at self-induction would otherwisehave been developed.

2. The method substantially as hereinbefore described, of reducingcounter electromotive force of self-induction, in alternatingcurrentmachines, by employing air-space resistance in those armature magneticcircuits at which self-induction would otherwise have been developed.

3. The method, substantially as hereinbefore described, ofconvertinft,rthe energy of alternating electric currents into effective mechanicalenergy, which consists in eliminating counter electromotive force ofself-induction from alternating-current machines, by establishing`biiilar or inductionless circuits at appropriate portions ofarmature-circuits, supplemented by air-space resistance adjacent to saidbifilar circuits, in those armature magnetic circuits at whichselfinduction would otherwise have been developed.

4. The method of reducing counter electromotive force of self-inductionin an alternating-current dynamo-electric machine, having commutatedarmature-circuits, which consists in reducing the self-induction of thefieldwindings with respect to that of the armature-windings.

5. The method, substantially as hereinbefore described, of convertingthe energy of alternating electric currents into effective mechanicalenergy, which consists in eliminating counter electromotive force ofself-induction from alternatiiig-current machines, by establishingbiiilar or inductionless circuits at appropriate portions of thearmature-circuits, and by reducing the self-induction of theeld-windings with respect to that of the armature-windings.

6. The method, substantially as hereinbefore described, of convertingthe energy of alternating electric currents into eifective mechanicalenergy, which consists in eliminating counter electromotive force ofself-induction from alternating-current machines, by reducing theself-induction of the iieldwindings with respect to that of thearmaturewindings, establishing bifilaror inductionless circuits atappropriate portions of the armature-circuits, and opposing a highmagnetic resistance to the fluxes in the local magnetic circuitssurrounding the armature-conductors.

7. The method of obviating the short-circuiting of the armature-coils ofan alternating-current dynamo-electric machine, which consists ingenerating by induction from said alternating current an opposingelectromotive force and balancing the electromotive force of thecommutated armature-circuits by said opposing electromotive force.

8. The method of obviating the short-circuiting of the armature-coils ofan alternating-current dynamo-electric machine, which consists ingenerating by induction from said alternating current an electromotiveforce and opposing the electromotive force of the IOO IIO

nel to the armature, but in close proximity thereto, in such a manner asto oppose the creation of a flux in local magnetic circuits surroundingthe armature-conductors.

11. The method of reducing the counter electromotive force ofself-induction in dynamo-electric machines, which consistsin 0pposing ahigh magnetic resistance to the fluxes in the local magnetic circuitssurrounding the armature-conductors RUDOLF EICKEMEYER,

Witnesses:

R. EICKEMEYER, J r., JOHN L. CLARK.

